Molecular Dynamics Simulation Study Of Protease PB92 And Its Mutants Before And After Substrate Binding

Protease PB92 is an important protein degradation component in detergents,so it has attracted the attention of academia and industry.At present,in order to reduce the cost of proteases and improve the performance of proteases,it is very important to find proteases that can change their properties.These characteristics include:higher thermal stability,lower low-humidity activity,higher specific activity under a given pH condition,change of Ca²⁺dependence,presence in other detergent ingredients(such as bleach,surfactant,etc.)Higher stability and so on.The binding process of enzyme and substrate is dynamic.The crystallographic study of protease PB92 can only provide us with the static conformation before and after binding of the enzyme to the substrate.For protease PB92,whether it is before or after binding to the substrate The structure,obtaining their molecular motion characteristics and dynamic details are very necessary for a comprehensive understanding of their functions.This information can provide a theoretical basis for the rational design and screening of protease PB92mutants with better performance,saving a lot of manpower,material resources and financial resources.Therefore,we used the method of molecular dynamics simulation to make three parts of the protease PB92and its mutants.First,we performed a long-term molecular dynamics simulation before and after the protease PB92 binds to the substrate,and obtained the important amino acid positions during the binding process of the protein PB92 to the substrate through dynamic information such as trajectory analysis,contact diagram,RMSD,and secondary structure.By combining the experimental data and the data obtained by molecular dynamics simulations,the mutations of residues 188,239,and 262 were selected,and the mutants PB92(A188P),PB92(Q239R),PB92(V262I)performed long-term molecular dynamics simulations before and after binding the substrate,and finally found that PB92(A188P)has the best stability in aqueous solution,and the stability of PB92(V262I)in aqueous solution is not as good as that before the mutant.The mutation was also obtained.Dynamic information and secondary structure changes during the substrate binding process of PB92(A188P),PB92(Q239R),and PB92(V262I).These data and results can provide a theoretical basis for the rational design of protease PB92 with better performance in the future.